CN114007501A

CN114007501A - Blood component measurement system, blood component measurement method, and blood component measurement program

Info

Publication number: CN114007501A
Application number: CN202080046527.1A
Authority: CN
Inventors: 薮崎克己; 加藤央大; 铃木京
Original assignee: Kowa Co Ltd
Current assignee: Kowa Co Ltd
Priority date: 2019-06-25
Filing date: 2020-06-24
Publication date: 2022-02-01
Also published as: EP3991643A4; WO2020262431A1; JPWO2020262431A1; US20220265170A1; EP3991643A1

Abstract

The purpose of the present invention is to provide a technique capable of improving the measurement accuracy of the concentration of a blood component. A blood component measurement system irradiates light to a measurement site of a living body while compressing the measurement site, and calculates a concentration of a predetermined blood component based on a pulse wave signal obtained based on light received from the measurement site. The blood component measurement system includes a processing unit that performs processing for analyzing the pulse wave signal to grasp a compression state of the measurement site, and a calculation unit that calculates a concentration of the blood component using the pulse wave signal during a period in which the compression state is grasped.

Description

Blood component measurement system, blood component measurement method, and blood component measurement program

Technical Field

The present invention relates to a blood component measurement system, a blood component measurement method, and a blood component measurement program.

Background

There are techniques such as: a measurement site of a living body is irradiated with light, a pulse wave signal is acquired based on the light received from the measurement site, and the concentration of a blood component is measured from the pulse wave signal. Patent document 1 discloses a technique in which: in a state where a measurement site of a living body is pressed, light is irradiated to the measurement site, a volume pulse wave is detected, a pressing force at which the amplitude of the volume pulse wave has the maximum value is determined as an optimum pressing force, then, measurement light is irradiated to the measurement site pressed with the optimum pressing force, and a blood glucose level is calculated based on a light reception result.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2016 + 112042.

Disclosure of Invention

Problems to be solved by the invention

The pulse wave is influenced by the daily period and changes all the time. The measurement result of the pulse wave signal changes depending on the magnitude of the force pressing the measurement site, and a good pulse wave signal cannot be obtained regardless of whether the force is too strong or too weak. In addition, when the pulse wave signal is acquired after the optimal pressing force is determined for the measurement site to measure the concentration of the blood component, for example, when the pressing force changes during measurement due to an external impact or the like, the change in the pressing force during measurement cannot be coped with, and an accurate pulse wave signal cannot be acquired. If an accurate pulse wave signal cannot be obtained, the accuracy of measuring the concentration of the blood component is lowered.

In view of the above circumstances, an object of the present disclosure is to provide a technique capable of improving the measurement accuracy of the concentration of a blood component.

Means for solving the problems

A blood component measurement system according to the present disclosure is a blood component measurement system that irradiates a measurement site of a living body with light while compressing the measurement site, and calculates a predetermined concentration of a blood component based on a pulse wave signal acquired based on the light received from the measurement site, the blood component measurement system including: a processing unit that analyzes the pulse wave signal to grasp a compression state of the measurement portion; and a calculation unit that calculates the concentration of the blood component using the pulse wave signal during the period in which the compression state is grasped. According to the blood component measurement system of the present disclosure, the pulse wave signal having an appropriate compression value for the measurement site can be used for the calculation of the concentration of the predetermined blood component, and therefore, the accuracy of measuring the concentration of the blood component can be improved.

In the blood component measurement system, the calculation unit may calculate the concentration of the blood component by selectively using the pulse wave signal acquired during a period in which a compression value for the measurement site is within a predetermined range.

In the blood component measurement system, the calculation unit may calculate the concentration of the blood component using the pulse wave signal acquired in a predetermined period, and may calculate the reliability of the concentration of the blood component based on the result of the processing in the predetermined period, and the blood component measurement system may further include a notification unit that notifies the concentration of the blood component when the reliability is equal to or higher than a predetermined value, and notifies the re-measurement of the concentration of the blood component when the reliability is insufficient at the predetermined value.

In the blood component measurement system, the processing unit may determine whether or not the compression value for the measurement site is within a predetermined range by performing the processing, and the processing may be continued for the pulse wave signal acquired after the compression value for the measurement site is determined to be within the predetermined range, and the calculation unit may calculate the concentration of the blood component using the pulse wave signal acquired after the compression value for the measurement site is determined to be within the predetermined range by the processing unit.

In addition, the present disclosure can be grasped from the aspect of a blood component measurement method or a blood component measurement program. For example, the blood component measurement method according to the present disclosure may be a blood component measurement method in which light is irradiated to a measurement site of a living body while the measurement site is compressed, and a predetermined concentration of a blood component is calculated based on a pulse wave signal obtained based on light received from the measurement site, wherein a process of analyzing the pulse wave signal to grasp a compression state of the measurement site is performed, and the concentration of the blood component is calculated using the pulse wave signal during a period in which the compression state is grasped.

Effects of the invention

According to the technique of the present disclosure, the measurement accuracy of the concentration of the blood component can be improved.

Drawings

Fig. 1 is a diagram showing an example of the configuration of a blood component measurement system according to an embodiment.

Fig. 2 is a diagram schematically showing a pulse wave signal measurement device in a blood component measurement system according to an embodiment.

Fig. 3 is a diagram schematically showing a part of a pulse wave signal measurement device in a blood component measurement system according to an embodiment.

Fig. 4 is a diagram schematically showing a part of a pulse wave signal measurement device in a blood component measurement system according to an embodiment.

Fig. 5 is a circuit diagram of a part of a pulse wave signal measurement device in a blood component measurement system according to an embodiment.

Fig. 6 is a graph showing an example of the pulse wave signal.

Fig. 7 is a graph illustrating an appropriate range of the compression value for the measurement site.

Fig. 8 is a graph illustrating a method for monitoring a compression value in a blood component measurement system according to an embodiment.

Fig. 9 is a graph illustrating frequency analysis of a pulse wave signal in the blood component measurement system according to the embodiment.

Fig. 10 is a graph illustrating a frequency analysis of a pulse wave signal in the blood component measurement system according to the embodiment.

Fig. 11 is a graph illustrating the inflection point count of a pulse wave signal in the blood component measurement system according to the embodiment.

Fig. 12 is a graph illustrating a method of comparing a reference pattern obtained from the shape of a plurality of beats in the blood component measurement system according to the embodiment.

Fig. 13 is a graph illustrating a method of comparing a sawtooth wave obtained from a shape of a single beat in the blood component measurement system according to the embodiment.

Fig. 14 is a graph illustrating a method of comparing a sawtooth wave obtained from a shape of a single beat in the blood component measurement system according to the embodiment.

Fig. 15 is a graph illustrating a method of comparing a sawtooth wave obtained from a shape of a single beat in the blood component measurement system according to the embodiment.

Fig. 16 is a graph illustrating a method of comparing a sawtooth wave obtained from a shape of a single beat in the blood component measurement system according to the embodiment.

Fig. 17 is a flowchart showing a blood component measurement process using the blood component measurement system according to one embodiment.

Detailed Description

Embodiments of the present invention will be described below with reference to the drawings. The configurations of the following embodiments are examples, and the present invention is not limited to the configurations of these embodiments.

First, the blood component measurement system according to the present embodiment will be described. Fig. 1 is a diagram showing a schematic configuration of a blood component measurement system 1 according to the present embodiment. As shown in fig. 1, the blood component measurement system 1 includes a pulse wave signal measurement device 100 and a terminal device 200.

The pulse wave signal measurement device 100 irradiates a measurement site, which is a part of a living body including blood, with near-infrared Light using a Light-Emitting Diode (LED), and receives the near-infrared Light having passed through the blood in the measurement site with Light using a photodiode (pd), thereby acquiring Light reception data. In a living body, light is not transmitted because it is opaque except for an eyeball and the like. However, for example, light entering the inside of a human finger is scattered by tissues, blood, and the like, and does not travel straight, and a small portion of the entering light reaches the PD and is detected. The component of the detected light intensity that fluctuates periodically is a pulse wave signal detected using light reception data of light that has passed through blood.

Here, a living body to be measured of the pulse wave signal measurement device 100 is a human being. When the measurement target is a human, the measurement site may be any site where pulsation can be easily detected by near infrared light, and preferably includes a finger, a palm, a wrist, an inner side of an elbow, a side of a knee, a sole, a toe, an earlobe, a front side of an ear, a lip, a chest, and the like, and more preferably includes a thumb, an index finger, and a middle finger, which can clearly detect pulsation. Hereinafter, the living body to be measured is referred to as a person, and the measurement site is referred to as a thumb. The living body to be measured and the measurement site are not limited to these.

The pulse wave signal measurement device 100 includes a control unit 110, a storage unit 120, an irradiation unit 130, a light receiving unit 140, a communication unit 150, and an operation unit 160. The control Unit 110 includes a Central Processing Unit (CPU) and controls each Unit in the pulse wave signal measurement device 100. The storage unit 120 includes a nonvolatile Memory such as a flash Memory or an Electrically Erasable Programmable Read-Only Memory (EEPROM), and a Random Access Memory (RAM). The storage unit 120 stores a control program in the pulse wave signal measurement device 100 and data obtained when various processes are executed.

The irradiation unit 130 irradiates a measurement site of a living body with near infrared light. In the present embodiment, the pulse wave signal measurement device 100 measures the pulse wave signal by irradiating the thumb of the person to be measured with near infrared light by the irradiation unit 130.

The intensity of light passing through blood in a blood vessel of a human finger periodically fluctuates according to pulsation of blood. The blood component measurement system 1 of the present embodiment measures a value of Triglyceride (hereinafter, referred to as "TG value in blood") in blood and a value indicating a ratio of glycated hemoglobin to a total hemoglobin concentration included in blood in percentage (hereinafter, referred to as "HbA 1c value") by non-invasively measuring the absorbance of blood at a plurality of wavelengths using a pulse wave signal that is a change over time in the light intensity of blood that has passed through the human thumb vessel.

When the concentration of TG value in blood increases and the turbidity of blood increases, the absorbance of near-infrared light having a wavelength of around 1050nm increases. Therefore, in the present embodiment, the TG value in blood is measured based on the difference between the absorbance of blood at a wavelength of 1050nm and the absorbance of blood at a wavelength of 1300 nm.

Further, the inventors of the present invention found that the absorbance at a wavelength of around 1450nm changes more greatly than other wavelengths according to the HbA1c value. Further, since the absorbance at a wavelength of about 900nm to 1300nm changes depending on the total hemoglobin concentration in blood, the HbA1c value is measured using the absorbance at 1450nm and the absorbance at 1050nm or 1300nm in the present embodiment.

In order to non-invasively measure the TG value and the HbA1c value in blood by irradiating the human finger with near infrared light of the above wavelengths, the irradiation unit 130 of the pulse wave signal measurement device 100 has an LED with a peak wavelength of 1050nm as the first light-emitting element, an LED with a peak wavelength of 1300nm as the second light-emitting element, and an LED with a peak wavelength of 1450nm as the third light-emitting element. The details of these LEDs and the methods of measuring the TG value and HbA1c value in blood will be described later.

The light receiving unit 140 receives light that has passed through blood in the measurement site. The near-infrared light irradiated by the irradiation unit 130 passes through blood contained in the measurement site of the living body, and is received by the light receiving unit 140. The light receiving unit 140 has a PD (photodiode), detects light that has passed through blood by the PD, and outputs the intensity thereof as a voltage signal. The pulse wave signal measurement device 100 includes an AD (Analog Digital) converter (not shown), and performs AD conversion on an output signal, which is light reception data, from the PD of the light reception unit 140, and outputs the output signal to the control unit 110. The control unit 110 stores the light reception data as a pulse wave signal in the storage unit 120. Further, the positional relationship of the irradiation section 130 and the light receiving section 140 will be described later.

The communication unit 150 performs wireless communication with the terminal device 200 by known short-range wireless communication such as Bluetooth (registered trademark), Bluetooth Low Energy (BLE), and Wi-Fi. The pulse wave signal measurement device 100 can transmit various data such as a pulse wave signal to the terminal device 200 or receive a control signal from the terminal device 200.

The operation unit 160 is configured by, for example, a button or a touch panel. The operation unit 160 operates to turn on/off the power supply, set communication with the terminal device 200, and the like.

Next, a terminal device 200 provided in the blood component measurement system 1 according to the present embodiment will be described. Examples of the terminal device 200 include a smartphone, a feature phone, a tablet personal computer, a notebook personal computer, a desktop personal computer, and various other electronic apparatuses. The terminal device 200 executes various processes in the blood component measurement described below (see fig. 17). In the present embodiment, the terminal device 200 is an example of a computer. In the blood component measurement system 1 according to the present embodiment, the terminal device 200 calculates the TG value and the HbA1c value in blood based on the pulse wave signal acquired by the pulse wave signal measurement device 100.

The terminal device 200 includes a control unit 210, a storage unit 220, a display unit 230, a communication unit 240, and an operation unit 250. The control unit 210 includes a CPU and controls each unit in the terminal apparatus 200. The storage unit 220 includes a RAM and a nonvolatile memory such as a Hard Disk Drive (HDD), a flash memory, and an EEPROM. The storage unit 220 stores a blood component measurement program, a control program, and data obtained when various processes are executed in the terminal device 200. In the control unit 210, the CPU executes the program stored in the storage unit 220, thereby realizing each functional unit of the processing unit 211 and the calculation unit 212. The processing unit 211 analyzes the pulse wave signal to grasp the compression state of the measurement site. The calculation unit 212 calculates the concentration of the blood component or calculates the reliability of the concentration of the blood component using the pulse wave signal.

The display unit 230 (an example of the "notification unit") is configured by a liquid crystal display device, an organic EL display device, or the like. The terminal device 200 displays the measurement values of the blood TG value and the HbA1c value and the reliability of the measurement values on the display unit 230.

The communication unit 240 can wirelessly communicate with the pulse wave signal measurement device 100 by known short-range wireless communication such as Bluetooth, BLE, or Wi-Fi, and can receive various data such as a pulse wave signal from the pulse wave signal measurement device 100 or can transmit a control signal to the pulse wave signal measurement device 100.

The operation unit 250 is configured by, for example, a button or a touch panel. The operation unit 250 operates to start measurement of the pulse wave signal, set communication with the pulse wave signal measurement device 100, and the like.

Next, a configuration example of the pulse wave signal measurement device 100 according to the present embodiment will be described in more detail with reference to fig. 2. Fig. 2 is an external perspective view of the pulse wave signal measurement device 100. The pulse wave signal measurement device 100 includes a housing 170, and an upper cover 171 that covers the upper portion of the housing 170. In the pulse wave signal measurement device 100, an opening 172 is provided between the housing 170 and the upper cover 171, and the opening 172 is used to insert a finger of a subject to be measured. The irradiation unit 130 and the light receiving unit 140 are provided on an abutment surface 170a, and the abutment surface 170a abuts against a finger of the subject in the housing 170 when the finger is inserted into the opening 172.

A knob 173 is provided on the upper cover 171, and the knob 173 is used to adjust the force with which the finger of the subject is pushed against the abutment surface 170 a. In the present embodiment, the knob 173 is engaged with a screw (not shown) penetrating the upper cover 171. A pressing plate (not shown) for pressing the finger of the subject is engaged with the tip of the screw. When the knob 173 is turned rightward, the screw and the pressing plate are lowered toward the contact surface 170a, and the pressing force of the pressing plate pressing the finger of the subject is increased. On the other hand, when the knob 173 is turned left, the screw and the pressing plate rise toward the upper cover 171 side, and the pressing force of the pressing plate pressing the finger of the subject decreases. The subject can adjust the force with which the finger is pushed against the contact surface 170a by turning the knob 173 to either the left or right side.

Fig. 3 is a diagram schematically showing a state in which the subject inserts the thumb 300 into the opening 172 in the pulse wave signal measurement device 100 shown in fig. 2. In the blood component measurement system according to the present embodiment, the pulse wave signal measurement device 100 employs a reflected light method in which the irradiation unit 130 irradiates light to the ventral side of the thumb 300 and the light that has passed through the blood is received by the light receiving unit 140 disposed on the ventral side.

Fig. 4 is a plan view showing a contact surface 170a on which the irradiation unit 130 and the light receiving unit 140 are arranged in the pulse wave signal measurement device 100. The irradiation unit 130 includes a first LED 131, a second LED 132, and a third LED 133. The first LED 131 irradiates light having a peak wavelength at 1050 nm. The second LED 132 irradiates light having a peak wavelength at a wavelength of 1300 nm. The third LED 133 irradiates light having a peak wavelength at 1450 nm.

In the present embodiment, the irradiation unit 130 irradiates light in the order of wavelengths from low to high in the biological transmissivity in the measurement region of the living body. Here, the lower the absorptivity of light in the living body, the higher the living body transmissivity, and the higher the absorptivity of light in the living body, the lower the living body transmissivity. In general, near-infrared light having a wavelength of 850 to 1500nm has a low in vivo absorption rate and a high in vivo transmittance. In the near-infrared light of the above wavelength, the biological transmissivity in the human finger is, in order from low to high, 1450nm, 1300nm, and 1050 nm. The controller 110 controls the irradiation unit 130 to irradiate light in the order of the lower transmittance of the living body, that is, in the order of the third LED 133, the second LED 132, and the first LED 131. As shown in fig. 4, the third LED 133 is disposed at the center of the 3 LEDs 131 to 133 arranged in parallel so as to be closest to the light receiving unit 40, and the third LED 133 irradiates light having a peak wavelength at a wavelength of 1450nm, and the biological transmittance at the wavelength of 1450nm is relatively low in the 3 wavelengths.

Further, the light receiving section 140 has a PD 141. The PD 141 receives light emitted from the irradiation unit 130 to the finger and passing through the blood. The PD 141 receives light optically, and outputs a voltage signal as light reception data.

Fig. 5 is a circuit diagram of a part of the pulse wave signal measurement device 100 according to the present embodiment. The pulse wave signal measurement device 100 includes a microcomputer 180 constituting the control unit 110 and the storage unit 120. The microcomputer 180 is operated by supplying electric power from a power source (e.g., a secondary battery), not shown, provided in the pulse wave signal measurement device 100. One end side (output terminal) of the PD 141 is connected to the microcomputer 180 via an RC parallel circuit (R =680k Ω, C =3 nF) in which a resistor 181 and a capacitor 182 are connected in parallel, and the other end side of the PD 141 is connected to the ground (grounded). The pulse wave signal measurement device 100 includes a transistor 183 (NPN type). In the transistor 183, a collector terminal is connected to the output terminal of the PD 141, an emitter terminal is connected to the ground, and a base terminal is connected to the microcomputer 180. The transistor 183 is an example of a switching element that switches between a connection state in which the output terminal of the PD 141 is connected to ground and a non-connection state in which the output terminal of the PD 141 is disconnected from ground.

The pulse wave signal measurement device 100 of the present embodiment obtains light reception data for 1 cycle by irradiating light of different wavelengths in the order of the third LED 133, the second LED 132, and the first LED 131 within a predetermined time (100 milliseconds). Through the transistor 183, the output terminal of the PD 141 is connected to the ground after light irradiation by the first LED 131 in a certain cycle, and the output terminal of the PD 141 is disconnected from the ground before light irradiation by the third LED 133 in the next cycle of the certain cycle. This allows the output signal of the PD 141 to be temporarily reset for each cycle. The microcomputer 180 controls switching of the transistor 183. A control program for executing this control is stored in a storage section (storage section 120 shown in fig. 1) of the microcomputer 180.

As shown in fig. 5, the anode terminals of the first LED 131, the second LED 132, and the third LED 133 are connected to a power supply circuit (not shown) that applies a 3.3V dc voltage, and the cathode terminals thereof are connected to collector terminals of transistors 184 to 186 (NPN type) via resistors. The emitter terminals of which of the transistors 184 to 186 are connected to the ground, and further, the base terminals of which of the transistors 184 to 186 are connected to the microcomputer 180 via resistors. The microcomputer 180 applies a voltage to the base terminals of the transistors 184 to 186 in accordance with the light irradiation timing of the first LED 131, the second LED 132, and the third LED 133, whereby a 3.3V dc voltage is applied to each LED. Thus, the pulse wave signal measurement device 100 can perform light irradiation of the first LED 131, the second LED 132, and the third LED 133 at predetermined timings. A control program for executing this control is stored in the storage unit (storage unit 120 shown in fig. 1) of the microcomputer 180.

Next, the pulse wave signal measured by the pulse wave signal measurement device 100 will be described with reference to fig. 6 (a) and 6 (b). When the pulse wave signal measurement device 100 measures a pulse wave, the magnitude of the force pressing the measurement site (hereinafter, simply referred to as "pressing value") affects the measurement result. In the present embodiment, the pulse wave signal measurement device 100 irradiates light to the ventral side of the thumb and receives light to the ventral side of the thumb, and therefore the pressure value on the ventral side of the thumb affects the measurement result.

Fig. 6 (a) is a graph showing an example of a pulse wave signal measured when the compression value for the measurement site is appropriate. Fig. 6 (b) is a graph showing an example of a pulse wave signal measured when the compression value for the measurement site is not appropriate. In the graphs of fig. 6 (a) and 6 (b), the horizontal axis represents time (seconds), and the vertical axis represents the intensity (arbitrary unit) of the amplitude. As shown in fig. 6 (a) and 6 (b), it is understood that a pulse wave signal in a favorable pulse state can be measured even when the compression value at the measurement site is appropriate.

Next, an appropriate range of the pressing value for the measurement site will be described with reference to fig. 7. Fig. 7 is a graph illustrating an appropriate range of the pressing value (hereinafter, referred to as "predetermined range") for the measurement site. Fig. 7 is a graph showing the magnitude of the intensity and amplitude of light received from the measurement site light by irradiating light having a peak wavelength of 1050nm while pressing the measurement site. In the graph of fig. 7, the horizontal axis represents the compression value (N), the left vertical axis represents the average value (arbitrary unit) of the light intensity of the light received by the light, and the right vertical axis represents the amplitude (arbitrary unit) of the light received by the light. Further, in the graph of fig. 7, a line a1 shows a change in the average value of light intensity with respect to the pressing value, and a line a2 shows a change in the amplitude with respect to the pressing value.

The blood vessel repeats contraction and expansion due to the pulsation of the heart, and the blood volume in the blood vessel changes along with the contraction and expansion. The pulse wave signal indicates a change in light intensity that has passed through a blood vessel in the measurement site due to a change in blood volume when light is irradiated to the measurement site. The greater the volume of blood through which light passes, the lower the intensity of light passing through the blood vessel, and the smaller the volume of blood through which light passes, the greater the intensity of light passing through the blood vessel. Therefore, by applying pressure to the measurement site so that the difference between the maximum value and the minimum value of the blood volume in the blood vessel that changes in accordance with the pulsation becomes relatively large, a good pulse wave signal can be measured.

In the present embodiment, the predetermined range of the compression value is set to a range in which the amplitude is 2 or more. As shown in the graph of fig. 7, the predetermined range of the compression value is, for example, about 2.7N to about 4.7N. In this way, the predetermined range of the compression value can be monitored based on the amplitude of the light received (the amplitude of the pulse wave signal). In the blood component measurement system 1 according to the present embodiment, the pulse wave signal measurement device 100 transmits the measured pulse wave signal to the terminal device 200 in real time. The terminal device 200 performs processing for analyzing the pulse wave signal received from the pulse wave signal measurement device 100 to grasp the state of compression on the measurement site.

Next, a method of monitoring the compression value will be described with reference to fig. 8 (a) to 8 (c). Fig. 8 (a) is a graph conceptually illustrating an example of the method of monitoring the compression value in the present embodiment. In the graph of fig. 8 (a), the horizontal axis represents time (seconds), and a line b1 shows a pulse wave signal. In this example, the monitoring period 1 is provided as a pulse wave signal measurement period until the compression value on the measurement site falls within a predetermined range. In the monitoring period 1, the pulse wave signal measurement device 100 lights the first LED 131, irradiates the thumb of the subject with light having a peak wavelength of 1050nm, receives the light having passed through the blood in the thumb with the PD 141, and measures the pulse wave signal. The pulse wave signal measurement device 100 transmits the measured pulse wave signal to the terminal device 200 in real time, and the terminal device 200 analyzes the pulse wave signal to determine whether or not the compression value on the measurement site falls within a predetermined range. When it is determined that the compression value of the measurement site is within the predetermined range, the terminal device 200 causes the pulse wave signal measurement device 100 to start measurement of the pulse wave signal for blood component measurement, thereby starting the monitoring period 2 (an example of "predetermined period"). The monitoring period 2 is a data acquisition period (about 20 seconds) for measuring a blood component, and the pulse wave signal measurement device 100 sequentially lights the first LED 131 to the third LED 133 in the monitoring period 2 to measure a pulse wave signal. The terminal device 200 calculates the TG value and the HbA1c value in blood based on the pulse wave signal acquired in the monitoring period 2. According to the blood component measurement system 1 of the present embodiment, the TG value and the HbA1c value in blood are calculated based on the pulse wave signal measured when the compression value on the measurement site is within the predetermined range, so that the measurement accuracy of the concentration of the blood component can be improved.

In this way, the first LED 131 is turned on in the monitoring period 1. This is because, in the monitoring period 1, the pulse wave signal for monitoring the compression value is measured, not the pulse wave signal for measuring the blood component, and the light reception data is acquired by irradiating light with one LED as compared with the case where a plurality of LEDs are sequentially turned on, whereby the number of light reception data can be increased, and therefore, the compression value can be analyzed in more detail than in the monitoring period 2. In the monitoring period 2, the terminal device 200 also analyzes the pulse wave signal obtained from the light emitted from the first LED 131 among the pulse wave signals for measuring blood components, and monitors the compression value.

Fig. 8 (b) is a graph conceptually illustrating an example of the method of monitoring the compression value in the present embodiment. In the graph of fig. 8 b, the horizontal axis represents time (seconds), and the line b2 and the line b3 show pulse wave signals. For the convenience of explanation, the line b2 and the line b3 are drawn by dividing into upper and lower 2 segments, but both show the same pulse wave signal. In this example, the evaluation of the compression value is repeated while the evaluation intervals per unit time are shifted in time, and the pulse wave signal for measuring the blood component is acquired after the compression value has reached the evaluation interval in the predetermined range. In this example, the first LED 131 is turned on to measure the pulse wave signal for monitoring the compression value in the evaluation interval before the compression value falls within the predetermined range, and the first LED 131 to the third LED 133 are sequentially turned on to measure the pulse wave signal for measuring the blood component in the evaluation interval after the compression value falls within the predetermined range. As shown in the graph of fig. 8 b, although the compression value is outside the predetermined range in the evaluation interval 1, the terminal device 200 determines that the compression value is within the predetermined range in the evaluation interval N (N is a natural number of 2 or more), and in this case, the pulse wave signal measurement device 100 measures the pulse wave signal for blood component measurement for about 20 seconds (an example of the "predetermined period") after the start of the evaluation interval N. The terminal device 200 calculates the TG value and the HbA1c value in blood based on the pulse wave signal for measuring a blood component in an amount of about 20 seconds. According to the blood component measurement system 1 of the present embodiment, the TG value and the HbA1c value in blood are calculated based on the pulse wave signal measured when the compression value on the measurement site falls within the predetermined range, so that the measurement accuracy of the concentration of the blood component can be improved.

Fig. 8 (c) is a graph conceptually illustrating an example of the method of monitoring the compression value in the present embodiment. In the graph of fig. 8 c, the horizontal axis represents time (seconds), and the line b4 shows the pulse wave signal. In this example, a case where the compression value is changed before the acquisition of the pulse wave signal for blood component measurement is completed is described. In this example, the first LED 131 is turned on to measure the pulse wave signal for monitoring the compression value before the compression value first falls within the predetermined range, and the first LED 131 to the third LED 133 are sequentially turned on to measure the pulse wave signal for measuring the blood component after the compression value first falls within the predetermined range. For example, as shown in the graph of fig. 8 c, when the terminal device 200 determines that the compression value is first within the predetermined range based on the pulse wave signal for compression value monitoring, the pulse wave signal measurement device 100 measures the pulse wave signal for blood component measurement (data a is acquired in fig. 8 c). The terminal device 200 continues monitoring of the compression value based on the acquired data a, and when it is determined that the compression value is out of the predetermined range before the measurement time of the acquired data a reaches a predetermined period (about 20 seconds), then, the pulse wave signal (in fig. 8 (c), the acquired data B) acquired after it is determined that the compression value is within the predetermined range is used as the pulse wave signal for measuring the blood component. The terminal device 200 causes the pulse wave signal measurement device 100 to measure the pulse wave signal for measuring the blood component so that the measurement time of the total of the acquisition data a and the acquisition data B becomes a predetermined period, and calculates the blood TG value and the HbA1c value based on the pulse wave signals of the acquisition data a and the acquisition data B. As in this example, the pulse wave signal for measuring blood components can be obtained by dividing it into 2 or more. The blood component measurement system 1 of the present embodiment always monitors the compression value because the concentration of the blood component is calculated based on the pulse wave signal during the period in which the compression value within the predetermined range is applied to the measurement site. Thus, in the blood component measurement system 1, even when the pressure value at the measurement site is changed to be out of the predetermined range in the measurement of the pulse wave signal for blood component measurement, the processing unit 211 grasps the change in the pressure value, and the calculation unit 212 calculates the concentration of the blood component by selectively using the pulse wave signal acquired during the period in which the pressure value at the measurement site is again within the predetermined range. Thus, the blood component measurement system 1 can improve the measurement accuracy of the concentration of the blood component.

Next, a processing method for grasping the pressing state of the measurement site will be described in detail. In the present embodiment, the pressing state of the measurement site is grasped by performing an analysis in which the pressing value is digitized. In the present embodiment, as an analysis method for digitizing the compression value, the following is exemplified: the pulse wave signal is analyzed by a frequency analysis, the count of the inflection point of the pulse wave signal, a comparison with a reference pattern obtained from the shapes of a plurality of pulses in the pulse wave signal, and a comparison with a sawtooth wave obtained from the shape of a single pulse in the pulse wave signal.

First, frequency analysis is explained. Fig. 9 (a) is a graph showing an example of the pulse wave signal measured by the pulse wave signal measurement device 100 when the compression value on the measurement site is within a predetermined range. In the graph of fig. 9 (a), the horizontal axis represents time (seconds), the vertical axis represents the intensity of amplitude (arbitrary unit), and the line c1 represents the pulse wave signal. Fig. 9 (b) is a graph showing an amplitude spectrum of a signal component for each frequency of the pulse wave signal obtained by fourier transforming the pulse wave signal shown in fig. 9 (a) for each unit time. In the graph of fig. 9 b, the horizontal axis represents frequency (Hz), the vertical axis represents amplitude (arbitrary unit), and the line c2 represents the amplitude spectrum.

On the other hand, fig. 10 (a) is a graph showing an example of the pulse wave signal measured by the pulse wave signal measurement device 100 when the compression value on the measurement site is outside the predetermined range. In the graph of fig. 10 (a), the horizontal axis represents time (seconds), the vertical axis represents the intensity of amplitude (arbitrary unit), and the line d1 represents the pulse wave signal. Fig. 10 (b) is a graph showing an amplitude spectrum of a signal component for each frequency of the pulse wave signal obtained by fourier transforming the pulse wave signal shown in fig. 10 (a) for each time unit. In the graph of fig. 10 b, the horizontal axis represents frequency (Hz), the vertical axis represents amplitude (arbitrary unit), and the line d2 represents the amplitude spectrum.

As shown in fig. 9 (b) and 10 (b), the maximum amplitude (amplitude corresponding to the frequency of pulsation) after fourier transform of the pulse wave signal measured when the compression value of the measurement site is within the predetermined range is larger than the pulse wave signal measured when the compression value of the measurement site is outside the predetermined range. In this way, since there is a correlation between the compression value at the measurement site and the maximum amplitude of the pulse wave signal after fourier transform, the correlation between the predetermined range of the compression value and the maximum amplitude of the pulse wave signal after fourier transform can be measured in advance, and the compression value can be digitized from the maximum amplitude of the pulse wave signal after fourier transform. In the frequency analysis in the present embodiment, the pulse wave signal may be normalized by the amplitude of the pulse before fourier transform. Even when such normalization is performed, the correlation between the maximum amplitude of the pulse wave signal after fourier transform and the compression value for the measurement site does not change.

Next, the inflection point count of the pulse wave signal will be described. Fig. 11 (a) is a graph showing an example of the pulse wave signal measured by the pulse wave signal measurement device 100 when the compression value on the measurement site is within a predetermined range. Fig. 11 (b) is a graph showing an example of the pulse wave signal measured by the pulse wave signal measurement device 100 when the compression value on the measurement site is outside the predetermined range. Fig. 11 (a) and 11 (b) show pulse wave signals of 2 beats.

In the amount of 1 beat of the pulse wave signal, as an inflection point, there are a set of a minimum point and a maximum point, and a notch (notch). Here, the pulse wave signal is formed by superposing a forward-going kick wave generated by the kick of blood and a backward-going reflected wave generated by the reflection from the tip, and a depression at the boundary between the kick wave and the reflected wave is defined as a concave point.

In the inflection point count of the pulse wave signal in the present embodiment, the minimum point, the maximum point, and the dip point are removed from the inflection point to be counted. As shown in fig. 11 (a), in the pulse wave signal measured when the compression value to the measurement site is within the predetermined range, there are no inflection points other than the minimum point, the maximum point, and the dip point, and the number of inflection points to be counted is "0". On the other hand, as shown in fig. 11 (b), in the pulse wave signal measured when the compression value to the measurement site is outside the predetermined range, inflection points (in the figure, points 1 to 6) are present in addition to the minimum point, the maximum point, and the dip point, and the number of inflection points to be counted is "6".

Here, the number of inflection points to be counted is small in a good pulse wave signal, and the number of inflection points to be counted is "0" in an ideal pulse wave signal. On the other hand, in a poor pulse wave signal, the number of inflection points to be counted is relatively large. As described above, the pulse wave signal quality and the inflection point of the counting target show a correlation. Therefore, a correlation is observed between the pulse wave signal measured when the compression value to the measurement site is within the predetermined range and the inflection point of the counting target for each pulse wave signal measured when the compression value is outside the predetermined range. In the present embodiment, a correlation between the inflection point count of the pulse wave signal (for example, the number of inflection points to be counted in the pulse wave signal of 5 beats) and the compression value of the measurement site at the time of measuring the pulse wave signal can be obtained in advance, and the compression value can be digitized by using the number of inflection points.

Next, a comparison with a reference pattern obtained from the shapes of a plurality of beats (hereinafter, simply referred to as "comparison method 1") will be described. In comparative method 1, the pulse wave signal is divided into a plurality of pulse quantities, the pulse number quantities per unit time are superimposed, and the reference pulse is calculated by the additive average. Thus, in the comparative method 1, the total value of the euclidean distance between the reference pulse and the pulse to be evaluated is calculated. In the comparative method 1, the pulse at the time of calculating the reference pulse and the pulse to be evaluated are sequentially shifted one by one, and pulse wave signals corresponding to a plurality of pulses can be analyzed.

Fig. 12 (a) is a graph showing an example of a pulse wave signal. In the graph of fig. 12 (a), the horizontal axis represents time (seconds), and the vertical axis represents the intensity (arbitrary unit) of the amplitude. In this example, a method of calculating a reference beat by superimposing 5 beats surrounded by a broken line f1 shown in fig. 12 (a) and evaluating the beat surrounded by a broken line f2 shown in fig. 12 (a) is described.

Fig. 12 (b) is a graph in which the reference pulse and the pulse to be evaluated are superimposed. In the graph of fig. 12 (b), the horizontal axis represents time (seconds), the broken line g1 shows the reference pulse, and the line g2 shows the pulse of the evaluation target.

The more favorable the pulse wave signal, the smaller the total value of the euclidean distance between the reference pulse and the pulse of the evaluation target, and the more unfavorable the pulse wave signal, the larger the total value of the euclidean distance between the reference pulse and the pulse of the evaluation target. As described above, the correlation is observed between the quality of the pulse wave signal and the total value of the euclidean distances. Therefore, a correlation is observed between the pulse wave signal measured when the compression value of the measurement site is within the predetermined range and the sum of the pulse wave signals measured when the compression value is outside the predetermined range and the euclidean distance. In the comparison method 1 according to the present embodiment, a correlation between the total value of the euclidean distances and the compression value of the measurement site at the time of pulse wave signal measurement can be obtained in advance, and the compression value can be digitized using the total value of the euclidean distances.

Next, a comparison with a sawtooth wave obtained from the shape of a single beat (hereinafter, simply referred to as "comparison method 2") will be described. In the comparison method 2, the pulse wave signal is evaluated by considering the pattern of the pulse wave having the optimal shape obtained by connecting the trough and the peak of the pulse wave signal, and comparing the magnitude of the euclidean distance, which is the difference obtained by comparing the pulse wave signal with each pulse.

Fig. 13 (a) to 13 (c) show pulse wave signals divided in unit time. Here, in the pulse wave signal shown in fig. 13 (a), data (P) at a certain time is compared with a data sequence (D) including a point before and after the data (P). Here, data of 7 dots in total is set as a data sequence (D) for each of 3 dots before and after. When the data (P) matches the maximum value of the data sequence (D), the data (P) can be regarded as a peak in each beat.

Next, the trough in the beat can be extracted by sequentially moving the time of interest. For example, when the data (P) shown in fig. 13 (b) matches the minimum value of the data series (D), the data (P) can be regarded as a trough in each beat.

On the other hand, as shown in fig. 13 (c), when the data (P) does not match both the peak extracted in fig. 13 (a) and the trough extracted in fig. 13 (b), the data (P) can be regarded as not being either the peak or the trough.

By sequentially shifting the time points of interest in this manner, the peaks and troughs of each pulse in the pulse wave signal can be dynamically and almost instantaneously extracted from the pulse wave signal. The rectangle obtained by connecting the peaks and the valleys extracted in this way can be used as a comparison mode in evaluating the shape of the pulse wave signal.

The compression value of the measurement site can be digitized using the comparison pattern obtained by the above method. In the following example, the pulse wave signal is evaluated using the sum of euclidean distances between the pulse wave signal obtained by the measurement and the comparison pattern.

(comparative method 2-1)

Fig. 14 (a) is a graph showing an example of a good pulse wave signal measured when the compression value for the measurement site is appropriate. Fig. 14 (b) is a graph showing an example of a bad pulse wave signal measured when the compression value for the measurement site is inappropriate. In the graphs of fig. 14 (a) and 14 (b), the horizontal axis represents time (seconds), the vertical axis represents the intensity (arbitrary unit) of the amplitude, the solid lines h1 and h3 show the measured pulse wave signals, and the broken lines h2 and h4 show the comparison pattern. In the comparison method 2-1, the areas enclosed by the solid lines h1, h3 and the broken lines h2, h4 (in the figure, indicated by the upper right hatching (in the present example, only the amount of 1 beat) in the graphs of fig. 14 (a) and 14 (b)) are calculated from the euclidean distances between the good pulse wave signals and the bad pulse wave signals and the respective comparison patterns. In the graph of fig. 14 (a) and the graph of fig. 14 (b), the area value of the graph of fig. 14 (a) is larger. In the graph shown in fig. 14 (a), the average value of the area for the amount of 10 beats was 1.11, and in the graph shown in fig. 14 (b), it was 0.70. Although the total value of the euclidean distances between the solid line h1 and the broken line h2 is smaller than the total value of the euclidean distances between the solid line h3 and the broken line h4, the amplitude of the good pulse wave signal is larger than the amplitude of the bad pulse wave signal, and therefore the area value of the graph in fig. 14 (a) is larger. Further, the area values in each beat are shown in the graphs of fig. 14 (a) and 14 (b).

(comparative method 2-2)

Fig. 15 (a) is a graph showing an example of a good pulse wave signal measured when the compression value for the measurement site is appropriate. Fig. 15 (b) is a graph showing an example of a bad pulse wave signal measured when the compression value for the measurement site is inappropriate. In the graphs of fig. 15 (a) and 15 (b), the horizontal axis represents time (seconds), the vertical axis represents intensity (arbitrary unit) of amplitude, solid lines i1 and i3 show measured pulse wave signals, and broken lines i2 and i4 show comparison patterns. Note that the pulse wave signals shown in fig. 15 (a) and 15 (b) are normalized with respect to the magnitude of the amplitude of the pulse.

In the comparison method 2-2, as in the comparison method 2-1, areas (indicated by hatching lines on the upper right in the drawing (in the present example, only the amount of 1 beat is shown)) surrounded by solid lines i1, i3 and broken lines i2, i4 in the graphs of fig. 15 (a) and 15 (b) are calculated from euclidean distances between the pulse wave signals and the comparison patterns. In the graph of fig. 15 (a) and the graph of fig. 15 (b), the area value of the graph of fig. 15 (b) is larger. In the graph shown in fig. 15 (a), the average value of the area of the amount of 10 beats is 0.14, and in the graph shown in fig. 15 (b), it is 0.23. The comparison method 2-2 can use the size of the area as an index of the pulse wave signal. Further, the area values in each beat are shown in the graphs of fig. 15 (a) and 15 (b).

Here, although the problem in the above-described comparative method 2-1 is solved by normalizing the amplitude from the pulse wave signal corresponding to the amount of 10 beats in the comparative method 2-2, this normalization method is not preferable in the case where the measurement time of the pulse wave signal is assumed to be about 10 seconds when the heart rate is 60 beats/minute and the compression state of the measurement site is monitored (for example, the monitoring period 1 shown in fig. 8 (a)) in order to obtain the pulse wave signal corresponding to the amount of 10 beats. Therefore, it is better to normalize the pulse wave signal according to as few beats as possible. On the other hand, when the normalization is performed based on the number of beats corresponding to 1, since the normalization accuracy is poor, it is preferable to determine the number of beats to be used for the normalization from both the accuracy and the immediacy.

(comparative method 2-3)

Fig. 16 (a) is a graph showing an example of a good pulse wave signal measured when the compression value for the measurement site is appropriate. Fig. 16 (b) is a graph showing an example of a bad pulse wave signal measured when the compression value for the measurement site is inappropriate. In the graphs of fig. 16 (a) and 16 (b), the horizontal axis represents time (seconds), the vertical axis represents the intensity (arbitrary unit) of the amplitude, the solid lines j1 and j3 show the measured pulse wave signals, and the broken lines j2 and j4 show the comparison pattern. Note that the pulse wave signals shown in fig. 16 (a) and 16 (b) are normalized with respect to the magnitude of the amplitude of the pulse.

In the comparison method 2-3, unlike the comparison method 2-1 and the comparison method 2-2, the area of a triangle (a region shown by dot hatching in fig. 16 a and 16 b) formed by three points of the trough, the peak, and the trough of the beat is calculated, and the ratio of the area (a region shown by upward right hatching in the figure) is calculated, whereby the deviation from the comparison pattern can be quantified. Fig. 16 (a) and 16 (b) show numerically how much each beat obtained by the comparison method 2-3 is deviated from the triangle. The larger the value, the larger the deviation of the measured pulse wave signal from the comparison pattern. The average value of the deviation between the measured pulse wave signal calculated from the amount of 10 beats and the comparison pattern is 0.16 in the case shown in fig. 16 (a) and 0.30 in the case shown in fig. 16 (b).

The comparison method 2-3 has an advantage that the comparison pattern is a triangle of 1 beat formed by the trough and peak of the beat, and thus the state of the pulse wave signal can be digitized in real time. Further, since the rate of deviation from the triangle of the pulse can be expressed in numerical values, the state score of the pulse wave signal can be expressed as a range or percentage of 0 to 1 by subtracting the value obtained from 1. For example, in the graph of fig. 16 (a), the fraction of the pulse wave signal obtained from the amount of 10 beats is 0.84 (84%), and in the graph of fig. 16 (b), the fraction of the pulse wave signal obtained from the amount of 10 beats is 0.70 (70%).

As described above, the pulse wave signal quality and the sum of the euclidean distances from the comparison pattern are correlated with each other. Therefore, a correlation is observed between the pulse wave signal measured when the compression value for the measurement site is within the predetermined range and the sum of the pulse wave signals measured when the compression value is outside the predetermined range and the euclidean distance. In the comparison method 2 according to the present embodiment, a correlation between the total value of the euclidean distances and the compression value of the measurement site at the time of pulse wave signal measurement can be obtained in advance, and the compression value can be digitized using the total value of the euclidean distances.

In the present embodiment, the method of comparing the maximum value and the minimum value of the data (P) and the data sequence (D) at the time of interest using the total of 7 points of the first 3 points and the last 3 points at the time of interest when extracting the trough and the peak from the pulse wave signal is exemplified, but the minimum point and the maximum point may be extracted by other methods. For example, the trough and the peak may be extracted by comparison with the magnitude relation or the differential value of the data points before and after a certain time.

In the present embodiment, the euclidean distance is calculated by taking the square root of the sum of squares of the deviation values from the pulse wave signal in the comparison mode, but the sum of the absolute values of the deviation values may be used for calculation of the euclidean distance.

Next, the measurement process of the blood component measurement system 1 according to the present embodiment will be described with reference to fig. 17. Fig. 17 is a flowchart relating to the measurement process executed by the blood component measurement system 1. The subject inserts the thumb into the opening 172 of the pulse wave signal measurement device 100 and turns the knob 173 to adjust the pressing force of the thumb against the contact surface 170 a. Next, the subject operates the terminal device 200 to start the blood component measurement.

First, the terminal device 200 transmits a measurement instruction of the pulse wave signal for determining the compression value to the pulse wave signal measurement device 100 in the OP 201. When receiving the measurement instruction from the OP 201, the pulse wave signal measurement device 100 starts the process of the OP 101. The pulse wave signal measurement device 100 lights the first LED 131 at the OP 101, irradiates the thumb of the subject with light having a peak wavelength of 1050nm, receives the light having passed through the blood in the finger with the PD 141, and measures the pulse wave signal. The pulse wave signal measurement device 100 transmits the measured pulse wave signal to the terminal device 200 in real time.

Next, the processing unit 211 of the terminal device 200 analyzes the pulse wave signal in the OP 202 (an example of "processing for grasping the compression state") to determine whether or not the compression value for the measurement site is within a predetermined range. As an analysis method of the pulse wave signal, the above-described analysis method of digitizing the compression value is exemplified.

When it is determined that the compression value is not within the predetermined range in the OP 202, the processing unit 211 proceeds to the processing of the OP 203. The terminal device 200 instructs the compression value correction to the subject at OP 203. For example, the terminal device 200 displays characters, images, and the like that instruct the correction of the compression value on the display unit 230. The subject rotates the knob 173 while referring to the characters or images displayed on the display unit 230 to adjust the pressing force of the thumb against the contact surface 170 a. The blood component measurement system 1 repeatedly executes the processing of OP 101, OP 202, and OP 203 until the compression value falls within the predetermined range. The period in which the processing of the OP 101, OP 202, and OP 203 is repeatedly executed is the monitoring period 1 shown in fig. 8 (a).

On the other hand, when the processing unit 211 determines that the compression value is within the predetermined range in the OP 201, the process proceeds to the processing of the OP 204. In the following OP 204, the terminal device 200 transmits an instruction to measure the pulse wave signal for measuring the blood component to the pulse wave signal measuring device 100.

When receiving the measurement instruction from the OP 204, the pulse wave signal measurement device 100 proceeds to the process of the OP 102. In OP 102, the pulse wave signal measurement device 100 measures a pulse wave signal for measuring a blood component. The pulse wave signal measurement device 100 irradiates the thumb of the subject with light in the order of the third LED 133, the second LED 132, and the first LED 131, and receives the light having passed through the blood in the finger with the PD 141, thereby acquiring light reception data. The pulse wave signal measurement device 100 acquires, for example, light reception data for 20 seconds (200 cycles), and uses the light reception data for 20 seconds as a pulse wave signal. The pulse wave signal measurement device 100 transmits the measured pulse wave signal to the terminal device 200 in real time. The period for measuring the pulse wave signal of 20 seconds is the monitoring period 2 shown in fig. 8 (a). The terminal device 200 receives the pulse wave signal at the OP 205, and the processing unit 211 performs the following processing: the state of pressure on the measurement site is grasped by analyzing the pulse wave signal obtained from the light emitted from the first LED 131 among the pulse wave signals for measuring blood components.

As described above, in the processing of OP 201 to 205, the processing unit 211 performs processing for grasping the pressing state of the measurement site, and thereby the terminal device 200 determines whether or not the pressing value of the measurement site is within the predetermined range. Then, in terminal device 200, processing unit 211 continues processing for grasping the compression state with respect to the pulse wave signal acquired after determining that the compression value for the measurement site is within the predetermined range, and calculation unit 212 calculates the concentration of the blood component in the processing from OP 206 to OP 208.

In the following OP 206, the calculation unit 212 of the terminal device 200 calculates the absorbance corresponding to each wavelength from the pulse wave signal. For example, the change width of the pulse wave signal corresponding to each wavelength can be appropriately converted into absorbance. The calculation unit 212 calculates the absorbance of blood corresponding to light irradiation at a wavelength of 1050nm (hereinafter referred to as "first absorbance"), the absorbance of blood corresponding to light irradiation at a wavelength of 1300nm (hereinafter referred to as "second absorbance"), and the absorbance of blood corresponding to light irradiation at a wavelength of 1450nm (hereinafter referred to as "third absorbance"), based on the change width of the pulse wave signal corresponding to the irradiation at each wavelength.

In the following OP 207, the calculation section 212 calculates a TG value in blood from the first absorbance and the second absorbance. The terminal device 200 calculates the non-invasive blood absorbance by, for example, performing a difference between the first absorbance and the second absorbance, and converts the non-invasive blood absorbance into a blood TG value using a predetermined conversion table. Thus, the blood TG value was calculated.

In the next OP 208, the calculation unit 212 normalizes the third absorbance, and converts the normalized third absorbance into an HbA1c value. As an example of normalization, for example, the third absorbance is divided by the first absorbance or the second absorbance. By normalizing the third absorbance, the HbA1c value can be calculated more accurately without depending on the total hemoglobin concentration. As a method of converting the normalized third absorbance into the HbA1c value, for example, data of a calibration line indicating a relationship between the absorbance and the HbA1c value prepared in advance is stored in the storage unit 220 of the terminal device 200, and the HbA1c value is calculated by comparing the normalized third absorbance with the calibration line. In the preparation of the calibration curve, human hemoglobin and glycated hemoglobin to be measured are preferably used.

In the following OP 209, the calculation unit 212 calculates the reliability of the measurement values of the TG value and the HbA1c value in the blood. The calculation unit 212 calculates the reliability by, for example, differentiating the pulse wave signal used for the blood component calculation by the above-described comparison method 2-2 or comparison method 2-3.

In the following OP 210, the calculation unit 212 determines whether or not the reliability is equal to or higher than a predetermined value (for example, equal to or higher than 0.8 (80%). When the calculation unit 212 determines that the reliability is not sufficient, the process proceeds to the process of the OP 212. In OP 212, the terminal device 200 notifies the subject of the remeasurement of the blood component by the display unit 230, and then executes the process of OP 201 again. Thus, the blood component measurement system 1 re-measures the concentration of the blood component.

On the other hand, when the reliability is determined to be the predetermined value or more by the OP 210, the calculation unit 212 proceeds to the processing of the OP 211. In the OP 211, the terminal apparatus 200 displays the TG value and the HbA1c value in blood and the reliability as the measurement result on the display unit 230. In this way, the terminal device 200 includes the display unit 230, and the display unit 230 notifies the concentration of the blood component when the reliability is equal to or higher than the predetermined value, and notifies the re-measurement of the concentration of the blood component when the reliability is insufficient. This enables the subject to know the TG value and the HbA1c value in the blood.

According to the present embodiment, since an accurate pulse wave signal can be detected, the accuracy of measuring the concentration of the blood component can be improved.

The above description has been made on the present embodiment, but the configuration of the pulse wave signal measurement device 100, the calculation process of the TG value and the HbA1c value in blood, and the like are not limited to the above-described embodiment, and various modifications can be made within the scope that is consistent with the technical idea of the present invention.

For example, in the above embodiment, the first LED 131 is turned on during a period until the compression value initially falls within the predetermined range, and the pulse wave signal for monitoring the compression value is measured. However, the LED to be turned on until the compression value initially reaches the predetermined range is not limited to the first LED 131, and may be the second LED 132 or the third LED 133. Even in a period before the compression value first becomes within the predetermined range, 2 or more LEDs can be turned on.

In the monitoring period 2 shown in fig. 8 (a), the processing unit 211 of the terminal device 200 may perform processing for grasping the state of pressure on the measurement site by analyzing the pulse wave signal obtained from the irradiation light of the second LED 132 or the third LED 133.

In the above embodiment, the measurement site of the living body is irradiated with light in the order of wavelength from low to high in biological transmissivity, but the biological transmissivity differs depending on the living body or the measurement site thereof. Therefore, the order of the wavelength from low to high in the biological transmissivity is not limited to 1450nm, 1300nm, and 1050 nm. The control of the irradiation of light in the order of wavelength from the lowest to the highest in the biological transmissivity may be performed based on a control signal from the terminal device 200. For example, the terminal device 200 stores biological transmissivity information of each wavelength in a measurement region of various living bodies, and the terminal device 200 may control the pulse wave signal measurement device 100 so that light is irradiated in the order of lower biological transmissivity to higher biological transmissivity in the measurement region of the living body to be measured.

In the present embodiment, the terminal device 200 calculates the concentration of the blood component based on the pulse wave signal measured by the pulse wave signal measurement device 100, but the present invention is not limited to this. The device for measuring the pulse wave signal and the device for calculating the concentration of the blood component may be the same or integrated. For example, when the apparatus for measuring the pulse wave signal is the same as the apparatus for calculating the concentration of the blood component, the pulse wave signal measurement apparatus 100 analyzes the pulse wave signal to grasp the compression state of the measurement site, and calculates the concentration of the blood component. In this case, the pulse wave signal measurement device 100 is an example of a computer in the present application.

Further, the terminal device 200 may transmit the pulse wave signal obtained by the pulse wave signal measurement device 100 to an external server that calculates the blood TG value and the HbA1c value based on the pulse wave signal via a communication line, transmit information including the blood TG value and the HbA1c value to the terminal device 200 via the communication line, and the terminal device 200 may display the blood TG value and the HbA1c value.

In the above-described embodiment, the pulse wave signal measurement device 100 employs the reflected light method, but may employ the transmitted light method. The pulse wave signal measurement device 100 of the transmission system may have the following configuration: for example, the irradiation unit 130 is disposed on the upper cover 171 such that the irradiation unit 130 and the light receiving unit 140 sandwich the thumb 300 of the subject inserted from the opening 172, the irradiation unit 130 irradiates light from the back side (nail side) of the thumb 300, and the light receiving unit 140 receives light passing through the thumb.

The number of LEDs included in the irradiation unit 130, the peak wavelength of the irradiation light of each LED, and the arrangement pattern are not limited to the above-described embodiments. For example, when only the TG value in blood is measured, the irradiation unit 130 may include the first LED 131 and the second LED 132. In the case of measuring only the HbA1c value, the irradiation unit 130 may include either the first LED 131 or the second LED 132, and the third LED 133.

In the above embodiment, the living body to be measured is a human, but the living body to be measured is not limited to a human. Examples of the specific measurement target organism include mammals and birds. Among them, it is more preferable to use a human, a mammal or a bird, which can be a pet or a livestock, that is likely to be diagnosed with a disease (e.g., diabetes) of hyperglycemia as a measurement target.

In the above embodiment, the TG value and the HbA1c value in blood were measured as the concentrations of blood components, but the concentrations of other blood components may be measured. For example, hemoglobin, glucose, cholesterol (total cholesterol, HDL-or LDL-cholesterol, free cholesterol), urea, bilirubin, lipoprotein, phospholipid, ethanol, and the like in blood can be measured. In this case, the living body is irradiated with light having a wavelength at which the absorbance changes depending on the concentration of each blood component, and the concentration of each blood component is calculated from the absorbance.

The method of digitizing the compression value described in the above embodiment is an example, and the compression value may be digitized by another analysis method.

In the above embodiment, the pressing force on the finger of the subject is adjusted by rotating the knob 173. However, the method of adjusting the pressing force is not limited thereto. For example, a strap of hook and loop fastener system may be provided, and the pressing force may be adjusted by retightening the strap. Further, the pressing force may be adjusted only by increasing or decreasing the force of the subject. Alternatively, a pressing mechanism driven by a motor may be provided, and the pressing force may be automatically adjusted in response to a signal from the terminal device 200.

In the above embodiment, the terminal device 200 includes the display unit 230 as the notification unit, but the notification unit is not limited to this. The terminal device 200 may include a speaker as a notification unit, and notify the concentration, reliability, and re-measurement of the blood component by sound. The terminal device 200 may include both the display unit 230 and a speaker as the notification unit.

Furthermore, from the viewpoint of stabilizing the pressing value to the measurement site that applies a biasing force to the contact surface 170a, the elastic member may be disposed between the upper cover 171 and the frame 170 so that the measurement site is sandwiched between the upper cover 171 and the contact surface 170 a.

The allowable range (a predetermined value or more) of the reliability of the concentration of the blood component may be changed depending on the biological state of the measurement target. For example, the allowable range of reliability may be set to be narrow when the living body to be measured is in a state before a meal, or may be set to be wide when the living body to be measured is in a state after a meal. The allowable range of the reliability of the concentration of the blood component may be changed according to the elapsed time from the eating time of the living body to be measured. For example, the longer the elapsed time from the eating time of the living body to be measured, the narrower the allowable range of the reliability can be set.

In the above embodiment, 3 LEDs having different emission wavelengths are used, but the number of LEDs and the type of emission wavelength of the LEDs required can be changed as appropriate by changing or increasing the blood component to be measured. In the pulse wave signal measurement device 100, a white LED or a halogen lamp may be used as the irradiation unit 130, or a spectroscope may be used as the light receiving unit 140. In such a case, according to the technique of the present disclosure, the measurement accuracy of the concentration of the blood component can be improved.

Description of reference numerals

1 blood component measuring System

100 pulse wave signal measuring device

200 terminal devices.

Claims

1. A blood component measurement system that irradiates light to a measurement site of a living body while compressing the measurement site, and calculates a concentration of a predetermined blood component based on a pulse wave signal acquired based on the light received from the measurement site, the blood component measurement system comprising:

a processing unit that analyzes the pulse wave signal to grasp a compression state of the measurement portion; and

and a calculation unit that calculates the concentration of the blood component using the pulse wave signal during the period in which the compression state is grasped.

2. A blood component measurement system according to claim 1,

the calculation unit calculates the concentration of the blood component by selectively using the pulse wave signal acquired during a period in which the compression value for the measurement site is within a predetermined range.

3. A blood component measurement system according to claim 1,

the calculation unit calculates the concentration of the blood component using the pulse wave signal acquired during a predetermined period, and calculates the reliability of the concentration of the blood component based on the result of the processing during the predetermined period,

the blood component measurement system further includes a notification unit that notifies the concentration of the blood component when the reliability is equal to or higher than a predetermined value, and notifies the re-measurement of the concentration of the blood component when the reliability is insufficient at the predetermined value.

4. A blood component measurement system according to any one of claims 1 to 3,

the processing unit performs the processing to determine whether or not the compression value for the measurement portion is within a predetermined range,

the processing unit continues the processing on the pulse wave signal acquired after determining that the compression value for the measurement site is within the predetermined range,

the calculation unit calculates the concentration of the blood component using the pulse wave signal acquired after the processing unit determines that the compression value for the measurement site is within the predetermined range.

5. A blood component measurement method for irradiating a measurement site of a living body with light while compressing the measurement site, and calculating a concentration of a predetermined blood component based on a pulse wave signal obtained based on the light received from the measurement site, characterized in that,

performing a process of analyzing the pulse wave signal to grasp a compression state of the measurement portion,

the concentration of the blood component is calculated using the pulse wave signal during the period in which the compression state is grasped.

6. The method of measuring a blood component according to claim 5,

selectively using the pulse wave signal acquired in a period in which the compression value for the measurement site is within a predetermined range, the concentration of the blood component is calculated.

7. The method of measuring a blood component according to claim 5,

calculating a concentration of the blood component using the pulse wave signal acquired within a predetermined period, and calculating a reliability of the concentration of the blood component based on a result of the processing in the predetermined period,

when the reliability is equal to or higher than a predetermined value, the concentration of the blood component is notified, and when the reliability is insufficient, the re-measurement of the concentration of the blood component is notified.

8. A blood component measuring method according to any one of claims 5 to 7,

determining whether or not the compression value for the measurement site is within a predetermined range by performing the processing,

continuing the processing on the pulse wave signal acquired after the compression value for the measurement site is determined to be within the predetermined range,

calculating the concentration of the blood component using the pulse wave signal acquired after determining that the compression value for the measurement site is within the predetermined range.

9. A blood component measurement program executed by a blood component measurement system that irradiates light to a measurement site of a living body while compressing the measurement site, and calculates a predetermined concentration of a blood component based on a pulse wave signal acquired based on light received from the measurement site, the blood component measurement program causing a computer to:

10. The blood component measurement program according to claim 9,

the computer is caused to selectively use the pulse wave signal acquired in a period in which a compression value for the measurement site is within a predetermined range, thereby calculating the concentration of the blood component.

11. The blood component measurement program according to claim 9, wherein the computer is caused to:

12. A blood component measurement program according to any one of claims 9 to 11, wherein the computer is caused to: